I know this is a question that will be all across the board for different vehicles, but we recently got our first hybrid. I'm at 211 miles now and the little indicator arrow shows the tank to be still slightly above the 3/4s of a tank mark. Are these little arrows reliable on most cars?

I ask because it looks like it will be quite some time before I'm able to go through a whole tank of gas, and I'm trying hard to get an indication of actual MPG useage. (I've heard there is an electronic feature for this, but I haven't learned how to use it yet... and even then without real world comparsion I won't trust the electronic feature until i can compare it with what we actually put into the car and then see on our odometer.)

Are the people here finding their tank gauges are accurate?